Merck’s trial of Keytruda regimen fails to meet primary endpoint

Merck & Co (MSD) announced that its Phase III KEYNOTE-B21 trial, studying Keytruda with chemotherapy in newly diagnosed high-risk endometrial cancer post-surgery, didn't meet its primary endpoint.

Sponsored by MSD, the trial involves collaboration with the European Network for Gynecologic Oncology Trial (ENGOT) groups and the GOG Foundation.

The randomized, double-blind study included 1,095 patients, assessing adjuvant Keytruda plus chemotherapy versus adjuvant placebo plus chemotherapy, with or without radiotherapy.

Primary endpoints were disease-free survival (DFS) and overall survival (OS), with safety as a secondary endpoint.

An interim analysis found no DFS improvement with Keytruda compared to placebo; OS wasn't assessed due to the lack of DFS superiority.

Keytruda's safety profile aligned with previous studies, with no new safety concerns.

Comprehensive data analysis is ongoing. Keytruda holds US approvals for advanced endometrial carcinoma treatment in various combinations and as a monotherapy for specific patient populations.